They are nitrogen, oxygen, hydrogen
<span>Gloria is writing the
chemical formula for a compound using its chemical name. She has just
identified the names of the elements in the compound. The tool that she will
need to use next is a textbook to learn the IUPAC naming of compounds or a
handbook of chemical compounds.</span>
Scientists can measure the height in
different units but problem could arise when they compare all the measurements.
That is the reason there is standard units for measurements.
<span>There may be error arises when an
American scientist is measuring the height of an object in inches and other Australian
scientist is measuring the height of same object in meters. Their data cannot
be compared because they are using different units to measure height.</span>
A chemical reaction is the process in which atoms present in the starting substances rearrange to give new chemical combinations present in the substances formed by the reaction. These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.
The enthalpy change is negative.
The other statements are false because:
Can take place without a catalyst
Energy is given out to the surroundings.
Kinetic energy of products is higher.
